453557-01-2Relevant academic research and scientific papers
A versatile strategy for the synthesis of functionalized 2,2′-bi- and 2,2′:6′,2′-terpyridines via their 1,2,4-triazine analogues
Kozhevnikov, Valery N.,Kozhevnikov, Dmitry N.,Nikitina, Tatiana V.,Rusinov, Vladimir L.,Chupakhin, Oleg N.,Zabel, Manfred,Koenig, Burkhard
, p. 2882 - 2888 (2007/10/03)
A general synthetic route for the synthesis of functionalized bi- and terpyridines is reported. Functionalized 1,2,4-triazene 4-oxides 7 and 8 - obtained from the reaction of hydrazones 1 with pyridine aldehydes and followed by oxidation - are functionalized by introduction of a cyano group via nucleophilic aromatic substitution. The thus-obtained 5-cyano-1,2,4-triazines 9 and 10 undergo facile inverse-electron-demand Diels-Alder reactions with enamines and alkenes to yield functionalized bi- and terpyridines, respectively. The substituent at position 6 of the 1,2,4-triazene 4-oxides must be aromatic or heteroaromatic in order to allow their facile synthesis, but other substituents and reagents may vary. Each step of the synthetic route allows diversification, which makes the approach particularly useful for the facile synthesis of a large variety of functionalized bi- and terpyridines.
Synthesis of functionalised bipyridines by sequential nucleophilic substitution of hydrogen and cycloaddition in 1,2,4-triazine rings
Kozhevnikov, Dmitry N.,Kozhevnikov, Valery N.,Nikitina, Tatiana V.,Rusinov, Vladimir L.,Chupakhin, Oleg N.,Neunhoeffer, Hans
, p. 30 - 32 (2007/10/03)
A new methodology for the synthesis of functionalised bipyridines by the direct cyanation of 3-(2-pyridyl)-1,2,4-triazine 4-oxide through nucleophilic substitution for hydrogen followed by the transformation of the 1,2,4-triazine ring into the pyridine ring by the Diels-Alder reaction and, finally, the chemical conversion of the cyano group is described.
